Author Topic: Standby generator  (Read 712 times)

nicky

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Standby generator
« on: June 14, 2020, 01:56:21 PM »
   I have a Lister  ST2 and I was considering the Harbour Freight 10kw generator head for a standby home generator. They seem to have pretty good reviews. The problem being is I don't want to run my Lister at 3600 rpm[if possible]. If I use pulleys at 2 to 1 ratio to keep my rpms at 1800 to 2000 rpms will the Lister have enough power to run the gen? I wouldnt be loading it to the max.
   I would just be running the LP furnace[in winter], 1/2 hp[220 volt]  well pump, some lighting and maybe an occasional 120 volt appliance.
   I am retired and on fixed income so money is a caution. That being the reason for the Harbour Freight gen head at $329.

old seagull man

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Re: Standby generator
« Reply #1 on: June 14, 2020, 03:51:53 PM »
Its been awhile but i think the ST2 was about 14.6 hp at 1800 rpm. So that's about 10.8 kw. So to run the engine at 1800 and the generator at 3600 your right about the 2:1 ratio, but you wont have the power the run the generator at its full 10kw.

My ZS195 10.3Kw will run my ST 7.5Kw  at almost full load.

So my guess is you would see about 7kw.

nicky

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Re: Standby generator
« Reply #2 on: June 18, 2020, 01:13:52 PM »
   Thank you for the reply.  I haven't added up the wattage I need but it would be minimal to some users. I have a 1/2 hp well pump, LP gas furnace, some lighting as needed and TV. I dont really need the water heater as that is a big user and not the electric range{ which I will be replacing it with LP].  I think maybe 3 to 4 KW will be plenty for an emergency generator and I could probably run it with my ST2 lister at 1800 rpms with a two to one pulley ratio. Am I correct in my thinking ??

nicky

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Re: Standby generator
« Reply #3 on: June 18, 2020, 01:29:38 PM »
   You kinda already answered this. Just wan't to be sure as this is all new to me.

mike90045

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Re: Standby generator
« Reply #4 on: June 18, 2020, 03:47:38 PM »
Running your well pump, you need a large enough alternator to manage the starting surge and the Power Factor of the lousy motor.

The engine flywheel should handle the starting surge (1 second) and the Power Factor is the style/quality of the core and windings of the alternator

Hugh Conway

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Re: Standby generator
« Reply #5 on: June 19, 2020, 01:45:49 AM »
@ Nicky. I think you are correct with your estimate of 3 to 4KW required.
My 6/1 drives a 3KW gen head which easily starts my 3/4Hp deep well pump. That's the biggest single load in my system.
It is an Utterpower PMG though, so is an overbuilt/underrated gen head.
I did have a 4.5KW Honda generator, it would also start the well pump, but was working hard.
The 6/1 with the PMG barely notices. Heavy flywheels help. 
Cheers
Hugh
JKson 6/1  (Utterpower PMG ) Off-grid
Lister 6/1 Start-O-Matic engine......running with PMG
1978 Royal Enfield (glutton for punishment by Indian iron)
1963 BMW R-27 project

nicky

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Re: Standby generator
« Reply #6 on: June 20, 2020, 01:32:35 PM »
   Thank you for the info. I just need to find an affordable generator head. :laugh: